Risk factors for mumps in children under 15 years of age during the transition from single-dose to two-dose MMR vaccination strategy: a matched case-control study

TL;DR

This study identifies risk factors for mumps in children under 15 during a shift from one to two doses of the MMR vaccine, helping guide public health strategies.

Contribution

The study provides new insights into risk factors for mumps during a transition to a two-dose MMR vaccination strategy.

Findings

Children aged 49–72 months had the highest proportion of mumps cases.

Factors like vaccination history and belief in vaccine efficacy reduced mumps risk, while crowded indoor exposure and vaccine hesitancy increased it.

Targeted interventions for high-risk groups could help control mumps outbreaks.

Abstract

This study aimed to investigate the risk factors for mumps in children under 15 years of age during the transition from a single-dose to a two-dose measles–mumps–rubella (MMR) vaccine strategy, providing a scientific basis for public health policies and interventions.

From the China Disease Prevention and Control (CDC) Information System, 547 children aged 0–14 years diagnosed with mumps in Taizhou City between 2021 and 2023 were included as cases. Controls were matched 1:1 and surveyed by the same investigator.

The analysis included 547 matched case-control pairs (343 males and 204 females) of children aged <15 years. The median age of the matched case-control pairs was 72 months. Among cases, children aged 49–72 months accounted for the highest proportion (28.52%). The multifactorial study showed that longer local residence (OR = 0.548, 95% CI 0.403 ~ 0.744), history of Mumps Component Vaccine (MuCV) (OR = 0.103, 95% CI 0.036 ~ 0.297), and belief that children would not get mumps (OR = 0.197, 95% CI 0.121 ~ 0.319) reduced the risk of mumps infection. In contrast, families with multiple births (OR = 1.926, 95% CI 1.405 ~ 2.640), being cared by someone other than parents (e.g., grandparents, babysitters, relatives or staff at a childcare center) (OR = 4.366, 95% CI 2.417 ~ 7.888), a higher level of the most frequently visited hospital (OR = 2.012, 95% CI 1.490 ~ 2.716), going into a crowded indoor place without wearing a mask (OR = 1.699, 95% CI 1.237 ~ 2.334), believing that mumps is not an infectious disease (OR = 1.782, 95% CI 1.274 ~ 2.492), believing that the disease is not serious (OR = 1.507, 95% CI 1.260 ~ 1.802), and believing that MuCV cannot prevent mumps (OR = 2.052, 95% CI 1.451 ~ 2.901) increased the risk of mumps infection.

For mumps prevention and control, targeted interventions should prioritize children aged 4–6 years and high-risk populations, including short-term residents, multi-child families, and childcare settings. Guardians should be encouraged to gain accurate knowledge about mumps and the protective effects of vaccination to mitigate vaccine hesitancy, ultimately controlling mumps outbreaks in the population.

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